HADOOP-10221. Add file missed in previous checkin, fix typo.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1579387 13f79535-47bb-0310-9956-ffa450edef68

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/security/SaslPropertiesResolver.java

@@ -0,0 +1,104 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.hadoop.security;
+
+import java.net.InetAddress;
+import java.util.Map;
+import java.util.TreeMap;
+
+import javax.security.sasl.Sasl;
+
+import org.apache.hadoop.conf.Configurable;
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.fs.CommonConfigurationKeysPublic;
+import org.apache.hadoop.security.SaslRpcServer.QualityOfProtection;
+import org.apache.hadoop.util.ReflectionUtils;
+import org.apache.hadoop.util.StringUtils;
+
+/**
+ * Provides SaslProperties to be used for a connection.
+ * The default implementation is to read the values from configuration.
+ * This class can be overridden to provide custom SaslProperties. 
+ * The custom class can be specified via configuration.
+ *
+ */
+public class SaslPropertiesResolver implements Configurable{
+  private Map<String,String> properties;
+  Configuration conf;
+
+  /**
+   * Returns an instance of SaslPropertiesResolver.
+   * Looks up the configuration to see if there is custom class specified.
+   * Constructs the instance by passing the configuration directly to the
+   * constructor to achieve thread safety using final fields.
+   * @param conf
+   * @return SaslPropertiesResolver
+   */
+  public static SaslPropertiesResolver getInstance(Configuration conf) {
+    Class<? extends SaslPropertiesResolver> clazz =
+      conf.getClass(
+          CommonConfigurationKeysPublic.HADOOP_SECURITY_SASL_PROPS_RESOLVER_CLASS,
+          SaslPropertiesResolver.class, SaslPropertiesResolver.class);
+    return ReflectionUtils.newInstance(clazz, conf);
+  }
+
+  @Override
+  public void setConf(Configuration conf) {
+    this.conf = conf;
+    properties = new TreeMap<String,String>();
+    String[] qop = conf.getTrimmedStrings(
+        CommonConfigurationKeysPublic.HADOOP_RPC_PROTECTION,
+        QualityOfProtection.AUTHENTICATION.toString());
+    for (int i=0; i < qop.length; i++) {
+      qop[i] = QualityOfProtection.valueOf(qop[i].toUpperCase()).getSaslQop();
+    }
+    properties.put(Sasl.QOP, StringUtils.join(",", qop));
+    properties.put(Sasl.SERVER_AUTH, "true");
+  }
+
+  @Override
+  public Configuration getConf() {
+    return conf;
+  }
+
+  /**
+   * The default Sasl Properties read from the configuration
+   * @return sasl Properties
+   */
+  protected Map<String,String> getDefaultProperties() {
+    return properties;
+  }
+
+  /**
+   * Identify the Sasl Properties to be used for a connection with a  client.
+   * @param clientAddress client's address
+   * @return the sasl properties to be used for the connection.
+   */
+  public Map<String, String> getServerProperties(InetAddress clientAddress){
+    return properties;
+  }
+
+  /**
+   * Identify the Sasl Properties to be used for a connection with a server.
+   * @param serverAddress server's address
+   * @return the sasl properties to be used for the connection.
+   */
+  public Map<String, String> getClientProperties(InetAddress serverAddress){
+    return properties;
+  }
+}